Spectra-Physics, Inc.

Bulletin Board

Vapor intrusion indoor air sampling is ongoing in the neighborhood around the site, and mitigation work is in progress at buildings found to be affected by vapor intrusion. EPA’s Fourth Five-Year Review was completed in Sept. 2014, concluding that the vapor intrusion investigation needs to be completed before a “protectiveness determination” can be made. See below for the latest information and reports.

Description and History

NPL Listing History

NPL Status: Final

Proposed Date: 06/24/88

Final Date: 02/11/91

Deleted Date:

The 11½-acre Spectra-Physics, Inc., site has been the location of a manufacturer of electronic equipment and gas lasers since 1961. Beginning in 1981, Spectra-Physics, Inc. stored its hazardous wastes on bermed concrete pads. Only one storage area has a cement floor without a berm, and that area is used for storing solid wastes. A variety of cleaners, degreasers, and lubricants are used in the manufacturing process. Wastes from manufacturing processes include volatile organic compounds (VOCs), paints, oils, acids, and bases. In 1981, the State discovered areas where hazardous wastes were stored that had no dikes or leachate collection systems. Additionally, several on-site wastewater sumps are suspected of contributing VOCs to the soils and groundwater. Contaminated groundwater from the site has moved off site to the north and merged with the contaminated plume of another NPL site, the Teledyne Semiconductor, Inc. site, which borders the Spectra-Physics, Inc. site. The two firms are jointly cleaning up the sites. Approximately 189,000 people live within a 3-mile radius of the site. The closest residence is located 200 feet southwest of the site. San Francisco Bay is 2½ miles downstream of the site and is used for recreation. The tides that influence the Bay also influence Permanente Creek, which is within 1 mile of the site. Several species of endangered birds are found within the area of tidal influence.

Contaminants and Risks

Contaminated Media

Groundwater

Surface Water

Soil and Sludges

Environmentally Sensitive Area

Soil contained VOCs, but has since been cleaned up. Groundwater is contaminated with VOCs. Drinking water is not affected by this contamination. Drinking water for this area comes from the Hetch Hetchy Reservoir in the Sierra Nevada, not from regional groundwater.

Who is Involved

Investigation and Cleanup Activities

Initial Actions

Initial Actions: In 1987, one wastewater sump was removed, and 6 feet of surrounding soils were excavated. In 1986 and 1988, an on-site shallow groundwater extraction well and one intermediate zone groundwater extraction well were installed. These wells were installed to prevent the plume of contaminants from migrating off site. Twenty additional wells were installed and have begun extracting groundwater from the off-site contaminant plume areas. Extracted groundwater is discharged to the City of Palo Alto sanitary sewer system. All actions were performed by Teledyne and Spectra-Physics.

Cleanup Ongoing

Since the late 1980s, Teledyne and Spectra-Physics have operated onsite and offsite groundwater extraction wells to remove TCE and hydraulically control the groundwater plume. In 2003, most of the groundwater extraction system was shut down due to decreased pollutant mass removal efficiency. In 2003, the Responsible Parties (RPs) pilot-tested and monitored natural attenuation for two years and concluded that this approach would not attain cleanup standards in a reasonable time.

In 2006, the Regional Board directed the RPs to re-characterize the Teledyne source property using high-resolution investigation technology to help focus further cleanup efforts. This work discovered and delineated previously unknown TCE hot spots at the site. In 2011, the dischargers pilot-tested an “in situ” method: enhanced bioremediation with recirculation. This involved injecting a carbohydrate solution as a food source for naturally occurring microbes, adding a microbial solution to accelerate the bioremediation process, and re-circulating the carbohydrate/microbe solution through a system of extraction and injection wells. The microbes consumed the carbohydrate solution and destroyed the TCE in place, creating harmless dechlorination byproducts such as carbon dioxide and salts.The pilot study reduced groundwater-TCE levels from as high as 80,000 parts per billion (ppb) to below 100 ppb, and in some wells to less than 5 ppb (the cleanup standard). This work is ongoing.

Cleanup Results to Date

The construction of all cleanup remedies is complete. The removal of sumps and contaminated soil and the installation of groundwater extraction wells have reduced the potential of exposure to contaminants at the Spectra-Physics, Inc. site while groundwater treatment is being completed.

The Fourth Five-Year Review was completed in Sept. 2014, concluding that the vapor intrusion indoor air investigation needs to be completed before a “protectiveness determination” can be made.

The following issues and recommendations were identified in the report:

Issue #1 – The performance of the selected remedy in the Record of Decision, groundwater extraction and treatment, has declined and new remedial actions are being investigated.

Recommendation – Complete a Record of Decision Amendment or prepare an Explanation of Significant Differences selecting new remedial actions and including updated institutional controls.

Issue #2 – The Five-Year Review vapor intrusion evaluation indicated that the subsurface-to-indoor air pathway is a concern at the site.

Recommendation – Continue to monitor and provide mitigation for vapor intrusion, including step-outs to lower concentration areas of the shallow TCE groundwater plume.

The Five-Year Review further stated the following:

A protectiveness determination of the remedy at the Teledyne Semiconductor and Spectra-Physics, Inc. Joint Superfund Sites cannot be made at this time until further information is obtained. Additional vapor intrusion assessments must be conducted to determine if indoor air pathways are complete. When unacceptable levels are encountered in a particular building, mitigation plans are developed and implemented to ensure that levels of volatile organic compounds (VOCs) in indoor air are protective. It is expected that these actions will take approximately two years to complete, at which time a protectiveness determination can be made. To be protective in the long-run, a new remedy should be selected due to the declining effectiveness of the existing remedy.